Phenobarbital is often effective in controlling partial and generalized tonic-clonic seizures.1
Phenobarbital often makes children and
Phenobarbital has the opposite effect on young and
middle-aged adults, who may feel:
Phenobarbital can alter your mood, behavior, thought
processes, and ability to learn or remember things. These effects may be worse
in older people.
The U.S. Food and Drug Administration (FDA) has
issued a warning on antiepileptic medicines and the risk of suicide and
suicidal thoughts. The FDA does not recommend that people stop using these
medicines. Instead, people who take antiepileptic medicine should be watched
warning signs of suicide. People who take
antiepileptic medicine and who are worried about this side effect should talk
to a doctor.
See Drug Reference for a full list of side effects.
(Drug Reference is not available in all systems.)
What To Think About
It may take time and careful,
controlled adjustments by you and your doctor to find the combination,
schedule, and dosing of medicine to best manage your epilepsy. The goal is to
prevent seizures while causing as few side effects as possible. After
you and your doctor figure out the medicine program that works best for you, make sure to follow your program exactly as prescribed.
Adverse effects. Phenobarbital's effect on your
thinking and state of mind is a serious drawback to using the drug. Teenagers
and adults taking the drug may feel depressed or irritable. It can cause memory
loss and decrease your ability to learn. Children and older adults may feel
restless and have trouble sleeping. Primidone is usually less
effective and has more side effects than phenobarbital (including depression
Drug interactions. Many medicines for epilepsy can
interact with other medicines you may be taking. This means that your epilepsy
medicine may not work as well, or it may affect the way another medicine you
are taking works. Some of these interactions can be dangerous. Make sure
to tell your doctor about all the medicines, herbal pills, and dietary
supplements you are taking. Phenobarbital may reduce the effectiveness of birth
Risk of birth defects. All medicines for epilepsy
have some risk of birth defects. But the risk of birth defects needs to be
carefully compared to other risks to the baby if the mother stops taking her
epilepsy medicine. If you are thinking about becoming pregnant, be sure
to plan ahead and talk with your doctor about the benefits and risks of taking
epilepsy medicine during your pregnancy. It you are already pregnant, it is not
too late. The best thing to do is talk to your doctor about your pregnancy
before you make any changes to the medicines you are taking.
Ease of use. Phenobarbital only has to be taken
once a day, making it a good choice if you have a busy schedule or have trouble
remembering to take your medicine. Because phenobarbital works very slowly, it
may take weeks before phenobarbital levels reach the proper level. But missing
a dose of phenobarbital now and then usually does not affect the drug levels in
your bloodstream. This is not true of other antiepileptic drugs.
Other concerns. For some people, phenobarbital may
cause side effects or carry risks that are not yet fully known. Report any
unexpected side effects or problems to your doctor.
Drugs for epilepsy (2008). Treatment Guidelines From The Medical Letter, 6(70): 37–46.
How this information was developed to help you make better health decisions.